The present invention relates to a projector for displaying an image on a viewing surface. More particularly, the invention concerns a projector configured to project an image perceivable as three-dimensional by a viewer.
In recent years, image projectors, and especially digital projectors, have found increased popularity as a tool for the presentation of many types of content to an audience. Typically, these projectors are used to project a computer-generated image onto a viewing surface. Image projectors allow a user to easily present high-quality images to audiences of a wide range of sizes. As a result, these projectors are now often found as permanent fixtures in conference rooms and other meeting facilities.
Images projected by typical image projectors generally appear flat and two-dimensional to a viewer, without any representation of depth other than the depth of field of the image. Such a representation may be suitable for many types of content. However, in some situations, it may be desirable to emphasize features of depth or texture in an image to a greater degree than is possible with a two-dimensional representation.
One way that a two-dimensional representation of an image may be given the appearance of depth is by representing the image stereographically. Stereographic images, commonly known as xe2x80x9cthree-dimensionalxe2x80x9d or xe2x80x9c3-Dxe2x80x9d images, appear to a viewer to have a dimension of depth. These images include separate, superimposed left-eye and right-eye images configured to mimic the slight differences in the appearance of a three-dimensional object as viewed by the left and right human eyes due to the separation of the eyes on the human face. The left-eye and right-eye images are presented such that the left-eye image is not perceived by the right eye of a viewer, and the right-eye image is not perceived by the left eye, typically via the aid of optical filters worn by the viewer.
Stereographic images have long been used to enhance visual effects in movies, books, and other media. However, current methods of presenting stereographic images suffer some drawbacks that may make them unsuitable for use in a meeting room environment. For example, one way a stereographic image may be presented in a meeting room environment is by using separate image projecting systems to project the left-eye image and the right-eye image. While such a system may be successfully used to form a stereographic image, the cost and the weight of the system may be much higher than that of a single projector. Furthermore, the two projectors may require a relatively difficult and time-consuming optical alignment. Also, such a system may be particularly difficult to move between locations due to the weight and bulk of the two systems, as well as the potentially difficult image alignment problems. In a meeting room context, these drawbacks may prove to be prohibitively difficult to overcome. Therefore, there remains a need for a stereographic projection system for the display of presentations that is suitable for use in a meeting room environment.
A projection system configured to project a stereographic image onto a viewing surface is provided, the stereographic image including a left-eye image and a right-eye image. The projection system includes a light source configured to produce a beam of light, a beam splitter configured to split the beam of light into a right image beam and a left image beam, an image engine configured to produce the stereographic image, and a projection lens configured to project the left-eye image and the right-eye image onto the viewing surface. The image engine includes a left optical path configured to produce the left-eye image from the left image beam, the left optical path including an upstream left polarizer, a left image-producing element and a downstream left polarizer, and a right optical path configured to produce the right-eye image from the right image beam, the right optical path including an upstream right polarizer, a right image-producing element and a downstream right polarizer.
Another aspect of the present invention provides a projection system configured to project a stereographic image onto a viewing surface, the stereographic image being configured to be perceived as three-dimensional by a viewer and including a left-eye image and a right-eye image. The projection system includes a light source configured to produce a beam of light, an image source configured to produce the left-eye image and the right-eye image in an alternating manner when illuminated by the beam of light, a polarizer configured to polarize the beam of light, thereby imparting a polarity to the beam of light, and a variable retarder configured to change the polarity of the beam of light in an alternating manner. The variable retarder has a first state and a second state and is synchronized to the image source to be in the first state when the image source produces the left-eye image and to be in the second state when the image source produces the right-eye image.
Yet another aspect of the present invention provides a stereographic adaptor configured to be removably attached to a projection system to impart stereographic projection capabilities to a non-stereographic projection system. The projection system includes a light source configured to produce a beam of light and an image source configured to produce a left-eye image and a right-eye image in an alternating fashion when illuminated by the beam of light. The stereographic adaptor comprises a frame, a polarizer disposed within the frame, the polarizer being configured to impart a polarity to the beam of light after the beam of light leaves the projection system, and a variable retarder positioned within the frame, optically downstream of the polarizer. The variable retarder is configured to optically rotate the polarity of the beam of light in an alternating fashion such that it is synchronized with the image source.